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                <h2>Tiling pattern designed by Donald Davies</h2>
                <p>The tiling pattern devised by Donald Davies for the entrance hall floor of the <strong>Charles Babbage Building</strong>, home of much of NPL's computing work from 1964 to 1996. The pattern was created with the help of similar pattern given on the cover page of the book "Turing's Legacy" - by David M Yates.<br/>This pattern was created in Inkscape 0.45. It took around 6 hours of continuous work to design this pattern. The <strong>pattern given on the book cover only contains blue and white coloured hexagons (with a black and few gray colored blocks)</strong>. Hence it is very hard to visualize the pattern. So <strong>we created the pattern in 6 colours (including white,gray and black)</strong> so that the pattern looks attractive and does not cause illusion to the viewer. We were quite fascinated by this pattern because it portrays the artistic work of Donald Davies.</p>
                <p><a href="archives/hexagon_array_32x24_coloured.svg">Scalable Vector Graphics (SVG)</a> was created by us using Inkscape 0.45. <a href="archives/hexagon_array_32x24_coloured.png">High resolution PNG</a> image is also available.</p>
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                    <img src="images/misc/DaviesPatter.jpg" alt="Tiling pattern designed by Donald Davies" >
                    <span>Tiling pattern designed by Donald Davies for the entrance hall floor of the Charles Babbage Building at NPL</span>
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                <h3>Floor tiles and the complex plane</h3>
                <p><i>Donald Davies's design for the tiling of the entrance hall floor in the new building is of interest to mathematicians. Complex numbers of the form a+bw ( where a and b are integers and w is one of the complex cube roots of unity) form a ring; that is, if any two are added, subtracted or multiplied you get another member of the set.</i></p>
                <p><i>Some members of this ring are prime in the sense that they cannot be expressed as the product of other members except in trivial ways. The hall floor represents the complex plane, with the origin at the center of the metal tile and the real axis pointing north. The centre of the hexagonal tiles are the members of the ring; primes correspond to dark tiles ( GREEN, BLUE, ORANGE ) and non-primes to light (WHITE). The pattern can be seen as 12 sectors, each a reflection of its neighbour in their common boundary. It has been used as the basis for the cover design on this book.</i></p>
                <p align="right"><i>From "Turing's Legacy" book - Page 59</i></p>
                <h2>Google search proves Davies is the UNSUNG Hero</h2>
                <p>The credit for development of packet-switched network paradigm is shared by Donald Watt Davies and Paul Baran. Google search results for the keyword "packet switching"+"Paul Baran" results in a whopping 26,000 results.</p>
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                    <img src="images/misc/google_search_pb.jpg" alt="Google search for the keyword 'packet switching'+'Paul Baran' returns 26,000 results." >
                    <span>Google search result for the keyword "packet switching"+"Paul Baran" (26,000 results) .</span>
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                <p>However, google search returns only 11,600 results for the keyword "packet switching"+"Donald Davies".</p>
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                    <img src="images/misc/google_search_dwd.jpg" alt="Google search for for the keyword 'packet switching'+'Donald Davies' returns 11,600 results" >
                    <span>Google search result for for the keyword 'packet switching'+'Donald Davies' (11,600 results) .</span>
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                <p>Google also thinks that Davies deserves to be portrayed as UNSUNG HERO :)</p>
                <p style="font-size: 1.4em"><i>NOTE: These search result were performed on June 29, 2007. The result count may vary in future when you enter the same keyword</i></p>
                <h2>Davies finds "first programming errors in existence"</h2>
                <p>A <a target="_new" href="http://en.wikipedia.org/wiki/Donald_Davies">wikipedia article on Donald Davies</a> says,</p>
                <p>"<i>From 1947, he worked with Alan Turing on the Pilot ACE computer and indeed spotted mistakes in Turing's seminal 1936 paper On Computable Numbers, much to Turing's annoyance. These were perhaps some of the first "programming" errors in existence, even if they were for a theoretical computer, the universal Turing machine.</i>"</p>
                <p>This is the only article to write about this incident ( first "programming" errors ). We have not come across any note or article that could verify this incident.</p>
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